Piperolein B and piperchabamide D isolated from black pepper (Piper nigrum L.) as larvicidal compounds against the diamondback moth (Plutella xylostella)

BACKGROUNDThere is growing demand for the development of alternative pest control agents that are effective as well as non-toxic to human health and the environment. Plant protection products derived from plant extracts are an eco-friendly alternative to synthetic pesticides. The aim of this study was to identify larvicidal compounds isolated from a natural source against Plutella xylostella L. In a larvicidal activity assay, several solvent fractions from the methanol extract of Piper nigrum L. fruit showed larvicidal effects against P. xylostella. RESULTSScreening results indicated that chloroform extract was the most effective against P. xylostella larvae. Two compounds with insecticidal activity in the chloroform fraction were identified as piperolein B and piperchabamide D by spectroscopic analyses, including mass spectrometry and NMR, and by comparison to published data. At applications of 0.1 mgmL(-1) concentration, piperolein B and piperchabamide D, respectively, induced 96.75.8% and 79.2 +/- 16.6% mortality rates of P. xylostella larvae 4 days post-application. CONCLUSION Our results demonstrate that piperolein B and piperchabamide D isolated from P. nigrum are the major constituents of the extract demonstrating insecticidal properties for the control of P. xylostella larvae. These plant-derived compounds should become useful alternatives to synthetic chemicals after studying their insecticidal mechanisms. (c) 2017 Society of Chemical Industry